An acylation reaction introduces an acyl functional group (R—C(═O)—) into a chemical compound by reaction with an acylating agent or acyl donor. Reactions of this type include transesterification of hydroxy compounds with esters to form a new ester plus co-product alcohol, and amidation of amines with esters to form amides plus co-product alcohol. For example, in the reaction of an alcohol with an acetate ester acylating agent, the acylating agent replaces the hydrogen atom of the alcohol hydroxyl group with an acetate group. Reactions similar to acylation include transamidation of amines with amides and transamination of ketones with amines. Alkyl acetates, such as methyl acetate and ethyl acetate, are commonly used acylating agents used to add an acetate functional group to organic compounds containing a hydroxyl group such as, for example, glycol ethers. This reaction of methyl acetate or ethyl acetate with the glycol ether is also known as transesterification. Transesterification is a reaction between an ester of one alcohol and a second alcohol to form an ester of the second alcohol and an alcohol from the original ester. The transesterification of methyl acetate, an ester of methanol, is of particular interest due to its relative abundance as a side product from the production of polyvinyl alcohol.
Acylation reactions (and similar reactions such as transamidation and transamination) commonly are limited by chemical equilibrium such that product and/or co-product must be removed from the reaction mixture to drive conversion to high levels needed for commercially feasible application. A well-known method of achieving this is to combine reaction with distillation in a reactive distillation operation. In reactive distillation, the transesterification reaction takes place in the distillation apparatus that is used to separate the products from the reaction mixture. This technique is especially useful for equilibrium-limited reactions, such as transesterification reactions. Conversion can be increased beyond what is expected by the equilibrium due to the continuous removal of reaction products from the reactive zone in the distillation apparatus. However, the use of reactive distillation often is complicated by the formation of azeotropic mixtures that are difficult to separate using distillation methods. As such, there is a need in the art for a process that can drive equilibrium limited reactions (e.g. acylation reactions) without needing to distill azeotropic mixtures.